TB, or tuberculosis, is a disease caused by bacteria called Mycobacterium tuberculosis. The bacteria can attack any part of the body, but usually attack the lungs. TB disease was once the leading cause of death in the United States. In the 1940s, scientists discovered the first of several drugs now used to treat TB. As a result, TB slowly began to disappear in the United States. However, drug resistant strains and infection of compromised patients has resulted in an increase in TB. Between 1985 and 1992, the number of TB cases increased; more than 16,000 cases were reported in 2000 in the United States. TB claims about 2 million lives every year. India, China, and Africa are hot spots, and the disease is increasing at a worrisome rate in Eastern Europe and nations that were formerly members of the Soviet Union.
TB is spread through the air from one person to another. The bacteria are put into the air when a person with TB disease of the lungs or throat coughs or sneezes. People nearby may breathe in these bacteria and become infected.
When a person breathes in TB bacteria, the bacteria can settle in the lungs and begin to grow. From there, they can move through the blood to other parts of the body, such as the kidney, spine, and brain. TB in the lungs or throat can be infectious. This means that the bacteria can be spread to other people. TB in other parts of the body, such as the kidney or spine, is usually not infectious. People with TB disease are most likely to spread it to people they spend time with every day. This includes family members, friends, and coworkers. People who are infected with latent TB do not feel sick, do not have any symptoms, and cannot spread TB, but they may develop TB disease at some time in the future. People with TB disease can be treated and cured if they seek medical help. Even better, people who have latent TB infection but are not yet sick can take medicine so that they will never develop TB disease.
Vaccination against TB currently involves needle injection of Bacille Camette-Guerin (BCG). This vaccine needs to refrigerated prior to delivery. However refrigeration is not always available, especially in developing countries. Lyophilization may be used to prepare a vaccine that is stable at room-temperature, if the molecule is not denatured during this procedure. However, when BCG is lyophilized most of its activity is lost. Therefore there is a need for a method for making a more stable vaccine for TB.
Currently drugs and vaccines for the treatment or prevention of TB are delivered to patients orally or by needle injections. A less painful and simpler method for delivering drugs and vaccines is needed. Getting patients to take a full course of drugs looms as one of the big problems in eradicating TB. After two to three months of treatment, the patients feel better, then they stop taking their medications. But they need six months of therapy to cure the disease. Drugs given by injection are painful and have toxic side effects. Pills are easier to take, but they, too, can cause liver and stomach problems including nausea, diarrhea, and vomiting.
There are several other major respiratory infectious diseases that suffer from the same deficiencies in treatment, including severe acute respiratory syndrome (SARS), meningococcal meningitis, influenza, Respiratory syncytial virus and small pox.
It is therefore an object of the invention to provide improved methods and formulations for use in decreasing or limiting the spread of tuberculosis and other infectious respiratory diseases.
It is another object of the invention to provide improved formulations for the treatment of tuberculosis and other infectious respiratory diseases which do not have to be injected.
It is another object of the invention to provide a more stable vaccine for TB and other infectious respiratory diseases and methods for making the vaccine.